Towards self-clocked gated OCDMA receiver

Abstract

A novel incoherent OCDMA receiver with incorporated all-optical clock recovery for self-synchronization of a time gate for the multi access interferences (MAI) suppression and minimizing the effect of data time jitter in incoherent OCDMA system was successfully developed and demonstrated. The solution was implemented and tested in a multiuser environment in an out of the laboratory OCDMA testbed with two-dimensional wavelength-hopping time-spreading coding scheme and OC-48 (2.5 Gbp/s) data rate. The self-clocked all-optical time gate uses SOA-based fibre ring laser optical clock, recovered all-optically from the received OCDMA traffic to control its switching window for cleaning the autocorrelation peak from the surrounding MAI. A wider eye opening was achieved when the all-optically recovered clock from received data was used for synchronization if compared to a static approach with the RF clock being generated by a RF synthesizer. Clean eye diagram was also achieved when recovered clock is used to drive time gating.

Enhanced probability density function using APD in SAC-OCDMA systems based SPD technique

“…For quite some time now, OCDMA has garnered remarkable research interests for its numerous benefits, such as asynchronism, simplified network topology, robust signal security, and flexibility in information rates [1,2]. Nevertheless, multiple-access interference (MAI) is the main constraint of performance and capacity in conventional OCDMA systems [3].…”

Towards higher scalability of hybrid optical CDMA network

“…All-optical time gating using MZI-SOA based time gate. The control signal for the picosecond selfclocked time gate was obtained from the all optical clock recovery circuit (AOCR)(Idris et al 2013b). SOA-semiconductor optical amplifier, MAI-multi access interference Eye diagram recorded at the output of the MZI-SOA time gate: a when the optical clock (control signal) is present; b in the absence of the optical clock…”